/* 基本重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

/* 全局CSS变量 */
:root {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #999999;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-hover: 0 5px 20px rgba(0,0,0,0.15);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --code-bg: #f4f4f4;
    --timeline-line: #e0e0e0;
    --timeline-dot: #3498db;
    --timeline-dot-border: #ffffff;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    --border-color: #475569;
    --shadow: 0 2px 10px rgba(0,0,0,0.4);
    --shadow-hover: 0 5px 20px rgba(0,0,0,0.6);
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --gradient-secondary: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
    --gradient-accent: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    --code-bg: #1e293b;
    --timeline-line: #475569;
    --timeline-dot: #818cf8;
    --timeline-dot-border: #334155;
}

body {
    font-family: 'Arial', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
.header {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    border-bottom: 1px solid var(--border-color);
}

.navbar {
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo h1 {
    color: var(--text-primary);
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

/* 语言切换器 */
.language-switcher {
    display: flex;
    gap: 0.5rem;
    margin-left: 2rem;
}

/* 主题切换器 */
.theme-switcher {
    margin-left: 1rem;
}

.theme-btn {
    background: none;
    border: 1px solid var(--text-secondary);
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-btn:hover {
    border-color: var(--text-primary);
    color: var(--text-primary);
    transform: scale(1.1);
}

.theme-btn i {
    transition: transform 0.3s ease;
}

.theme-btn:hover i {
    transform: rotate(180deg);
}

.lang-btn {
    padding: 0.5rem 1rem;
    border: 1px solid #60a5fa;
    background: transparent;
    color: #60a5fa;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
    text-decoration: none;
}

.lang-btn:hover {
    background: #60a5fa;
    color: var(--bg-primary);
    transform: translateY(-2px);
}

.lang-btn.active {
    background: #60a5fa;
    color: var(--bg-primary);
    box-shadow: 0 2px 8px rgba(96, 165, 250, 0.3);
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 5px;
}

.nav-link:hover {
    color: #60a5fa;
    background-color: var(--bg-card);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* 主要内容区域 */
main {
    margin-top: 80px;
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%),
                url('https://images.unsplash.com/photo-1517180102446-f3ece451e9d8?w=1920&h=1080&fit=crop') center/cover;
    color: white;
    text-align: center;
    padding: 100px 20px;
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.3);
    z-index: 1;
}

.hero-content {
    max-width: 800px;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease-out 0.3s both;
}

.cta-button {
    background: linear-gradient(45deg, #60a5fa, #3b82f6);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.1rem;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    animation: fadeInUp 1s ease-out 0.6s both;
    box-shadow: 0 5px 15px rgba(96, 165, 250, 0.3);
    position: relative;
    overflow: hidden;
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transition: left 0.5s ease;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(96, 165, 250, 0.4);
    background: linear-gradient(45deg, #3b82f6, #60a5fa);
}

.cta-button:hover::before {
    left: 100%;
}

/* 关于我部分 */
.about {
    padding: 60px 0;
    background: var(--bg-secondary);
    position: relative;
    overflow: hidden;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('https://images.unsplash.com/photo-1517180102446-f3ece451e9d8?w=1920&h=1080&fit=crop');
    background-size: cover;
    background-position: center;
    opacity: 0.1;
    z-index: 0;
}

.about .container {
    position: relative;
    z-index: 1;
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: #60a5fa;
    margin: 1rem auto;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 2rem;
    align-items: start;
    animation: fadeInUp 0.8s ease-out;
}

.about-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    animation: slideInRight 0.8s ease-out 0.4s both;
}

.about-text p {
    margin-bottom: 1rem;
    font-size: 1rem;
    line-height: 1.6;
}

.skills {
    margin-top: 2rem;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    border: 2px solid var(--border-color);
    margin-left: 1rem;
    margin-right: 1rem;
}

.skills h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-size: 1.5rem;
    position: relative;
    padding-left: 1.5rem;
    font-weight: 600;
}

.skills h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: #60a5fa;
    border-radius: 50%;
}

.skills-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
}

.skills-list li {
    background-color: var(--bg-primary);
    padding: 1.5rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    font-weight: 500;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.8rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
    font-size: 1rem;
}

.skills-list li:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    background-color: var(--bg-secondary);
    border-color: #3b82f6;
}

.skills-list li i {
    font-size: 2rem;
    width: 40px;
    height: 40px;
    text-align: center;
    color: #60a5fa;
    margin-bottom: 0.5rem;
    transition: all 0.3s ease;
}

/* 专业经历时间线 */
.experience {
    margin-top: 2rem;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    border: 2px solid var(--border-color);
    margin-left: 1rem;
    margin-right: 1rem;
}

.experience h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-size: 1.5rem;
    position: relative;
    padding-left: 1.5rem;
    font-weight: 600;
}

.experience h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: #10b981;
    border-radius: 50%;
}

.timeline {
    position: relative;
    padding-left: 1.5rem;
    margin-top: 1rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(to bottom, #60a5fa, #3b82f6);
}

.timeline-item {
    position: relative;
    margin-bottom: 1.5rem;
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    font-size: 1rem;
}

.timeline-item:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-hover);
    background: var(--bg-secondary);
    border-color: #3b82f6;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -2.5rem;
    top: 1.2rem;
    width: 16px;
    height: 16px;
    background: #60a5fa;
    border-radius: 50%;
    border: 3px solid var(--bg-secondary);
    box-shadow: 0 0 0 3px #60a5fa;
}

.timeline-year {
    font-weight: bold;
    color: #60a5fa;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    color: var(--text-primary);
    margin-bottom: 0.3rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.timeline-content p {
    color: var(--text-secondary);
    margin: 0;
    font-size: 0.9rem;
}

/* 个人成就 */
.achievements {
    margin-top: 2rem;
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    border: 2px solid var(--border-color);
    margin-left: 1rem;
    margin-right: 1rem;
}

.achievements h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    font-size: 1.5rem;
    position: relative;
    padding-left: 1.5rem;
    font-weight: 600;
}

.achievements h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: linear-gradient(45deg, #f59e0b, #fbbf24);
    border-radius: 50%;
}

.achievements-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.achievements-list li {
    background-color: var(--bg-primary);
    padding: 1.5rem;
    border-radius: 12px;
    border: 2px solid var(--border-color);
    font-weight: 500;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.2rem;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
    font-size: 1rem;
}

.achievements-list li:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    background-color: var(--bg-secondary);
    border-color: #f59e0b;
}

.achievements-list li i {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    color: #f59e0b;
    opacity: 0.3;
}

.about-image {
    text-align: center;
    position: sticky;
    top: 2rem;
    height: fit-content;
    animation: slideInLeft 0.8s ease-out 0.2s both;
}

.profile-image {
    width: 280px;
    height: 280px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: var(--shadow-hover);
    transition: all 0.3s ease;
    border: 4px solid var(--bg-card);
    position: relative;
}

.profile-image:hover {
    transform: scale(1.05);
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

/* 项目部分 */
.projects {
    padding: 80px 0;
    background-color: var(--bg-primary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.project-card {
    background: var(--bg-card);
    border-radius: 15px;
    box-shadow: var(--shadow-hover);
    transition: all 0.3s ease;
    position: relative;
    min-height: 500px;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
}

.project-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 25px 50px rgba(0,0,0,0.15);
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 1;
}

.project-card:hover::before {
    opacity: 1;
}

.project-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.project-card:hover .project-image {
    transform: scale(1.1);
}

.project-info {
    padding: 1.5rem;
    position: relative;
    z-index: 2;
    background: var(--bg-card);
    display: flex;
    flex-direction: column;
    height: auto;
    min-height: 300px;
}

.project-info h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.project-info p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.project-links {
    display: flex;
    gap: 1rem;
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    min-height: 60px;
    align-items: center;
    justify-content: center;
}

.project-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(45deg, #60a5fa, #3b82f6);
    color: white !important;
    text-decoration: none;
    border-radius: 25px;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: 0 4px 15px rgba(96, 165, 250, 0.3);
    position: relative;
    overflow: visible;
    flex: 1;
    min-width: 120px;
    gap: 0.5rem;
    z-index: 10;
}

.project-link:hover {
    background: linear-gradient(45deg, #3b82f6, #60a5fa);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(96, 165, 250, 0.4);
}

.project-link:active {
    transform: translateY(0);
}

/* 查看演示按钮 - 绿色主题 */
.project-link:first-child {
    background: linear-gradient(45deg, #10b981, #34d399);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.project-link:first-child:hover {
    background: linear-gradient(45deg, #34d399, #10b981);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

/* 源代码按钮 - 橙色主题 */
.project-link:last-child {
    background: linear-gradient(45deg, #f59e0b, #fbbf24);
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.3);
}

.project-link:last-child:hover {
    background: linear-gradient(45deg, #fbbf24, #f59e0b);
    box-shadow: 0 6px 20px rgba(245, 158, 11, 0.4);
}

.project-links a.project-link {
    color: white !important;
    text-decoration: none !important;
    opacity: 1 !important;
    visibility: visible !important;
}

/* 联系部分 */
.contact {
    padding: 80px 0;
    background-color: var(--bg-secondary);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
}

.contact-info h3,
.contact-form h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.contact-info p {
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.8;
}

.contact-details {
    margin-bottom: 2rem;
}

.contact-item {
    margin-bottom: 1rem;
    padding: 1rem;
    background-color: var(--bg-card);
    border-radius: 5px;
    border-left: 4px solid #60a5fa;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.contact-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-hover);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    background-color: var(--bg-card);
    color: var(--text-primary);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #60a5fa;
}

.submit-button {
    background: linear-gradient(45deg, #60a5fa, #3b82f6);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: bold;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    position: relative;
    overflow: hidden;
}

.submit-button:hover {
    background: linear-gradient(45deg, #3b82f6, #60a5fa);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(96, 165, 250, 0.3);
}

.submit-button:active {
    transform: translateY(0);
}

/* 社交媒体链接 */
.social-links-contact {
    margin-top: 2rem;
}

.social-links-contact h4 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-size: 1.2rem;
}

.social-links-contact .social-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.social-links-contact .social-link {
    background: linear-gradient(45deg, #60a5fa, #3b82f6);
    color: white;
    text-decoration: none;
    padding: 0.8rem 1.2rem;
    border-radius: 25px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border: none;
    font-weight: 500;
}

.social-links-contact .social-link:hover {
    background: linear-gradient(45deg, #3b82f6, #60a5fa);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(96, 165, 250, 0.3);
}

/* 页脚 */
.footer {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    text-align: center;
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
}

.footer .social-links {
    margin-top: 1rem;
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.footer .social-link {
    color: var(--text-primary);
    text-decoration: none;
    padding: 0.8rem 1.2rem;
    border-radius: 25px;
    background-color: var(--bg-card);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border: 1px solid var(--border-color);
}

.footer .social-link:hover {
    color: #60a5fa;
    background-color: var(--bg-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* 响应式设计 */
@media screen and (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-secondary);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .language-switcher {
        margin-left: 0;
        margin-top: 1rem;
        justify-content: center;
    }
    
    .lang-btn {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
    
    .theme-switcher {
        margin-left: 0.5rem;
    }
    
    .theme-btn {
        width: 35px;
        height: 35px;
        font-size: 0.9rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .about-image {
        position: relative;
        top: 0;
        order: -1;
    }
    
    .profile-image {
        width: 200px;
        height: 200px;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .skills-list {
        grid-template-columns: 1fr;
    }
    
    .timeline {
        padding-left: 1.5rem;
    }
    
    .timeline-item {
        padding: 0.8rem;
    }
    
    .timeline-item::before {
        left: -2rem;
    }
    
    .achievements-list {
        grid-template-columns: 1fr;
    }
    
    .skills, .experience, .achievements {
        padding: 1.5rem;
    }
    
    .social-links-contact .social-links {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .social-links-contact .social-link {
        flex: 1;
        min-width: 140px;
        text-align: center;
        justify-content: center;
    }
}

@media screen and (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 60px 15px;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .about,
    .projects,
    .contact {
        padding: 60px 0;
    }
    
    .profile-image {
        width: 200px;
        height: 200px;
    }
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(45deg, #60a5fa, #3b82f6);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    box-shadow: 0 4px 15px rgba(96, 165, 250, 0.3);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-3px) scale(1.1);
    box-shadow: 0 8px 25px rgba(96, 165, 250, 0.4);
}

.back-to-top:active {
    transform: translateY(-1px) scale(1.05);
}

/* 自定义滚动条 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: #60a5fa;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #3b82f6;
}

/* 打印样式 */
@media print {
    .header,
    .footer,
    .contact-form,
    .back-to-top {
        display: none;
    }
    
    main {
        margin-top: 0;
    }
    
    body {
        background-color: white;
        color: black;
    }
}